Electromagnetic compatibility (EMC) requires that electronic systems and equipment be able to tolerate a specified degree of interference and not generate more than a specified amount of electromagnetic interference (EMI). EMC is becoming more important because there are so many more opportunities today for EMC issues due to increased use of electronic devices e.g. in automotive, personal computing, entertainment, and communication applications. There is increased potential for EMI susceptibility in electronic devices due to lower supply voltages, higher clock frequencies that require faster slew rates, increased electronic packaging density. There is also an increased risk of generating EMI due to proximity of high voltage electrical systems, such as electric vehicle propulsion systems.
One approach to EMC is providing shielding against EMI. Options for electromagnetic shielding include forming a conductive enclosure around the electronic device, such as a metallic case or plastic case formed of a conductive plastic or coated with a conductive substance. The effectiveness of the electromagnetic shielding is typically limited by apertures and seams in the shield that may be required, examples of which are removable covers for access to the electronic device, ventilation holes, and openings required for control/display devices and electrical interconnection. Methods that may be employed to mitigate the shielding loss from apertures and seams include minimizing the size and number of apertures and seams, using conductive gaskets and/or flexible contacts to seal the interface between seams, maximizing the contact area at seams, and avoiding galvanic corrosion at seams.
High voltage cables in electrical vehicle propulsion system use shielded wire cables to mitigate emitted EMI. The continuity of the shielding must be preserved across interconnections of the cable, therefore the connectors for these shielded cables include shields surrounding the terminals of the connectors. In order for the connectors to be separable, the shields surrounding the terminals have at least two section which have a seam between them. The shields are typically interconnected by flexible contacts. The effectiveness of the shielding provided by the shields may depend on the normal spring force exerted by the flexible contacts of a first shield on a second mating shield, especially in a high vibration environment e.g., in an automobile. Such shields used in connectors are typically formed of sheet metal and the normal spring force exerted by the flexible contacts of a first shield be diminished by deformation of the sheet metal of the second shield caused by the flexible contacts, thus diminishing the electromagnetic shielding effectiveness of the connector system. Therefore, a connector system with improved electromagnetic shielding capability is desired.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.